microchatter

From:

Priscilla Delventhal

Hi to all in Histo land. I have read with interest the ever present
problem of microchatter. We seem to be honing in on many different
techniques to help with this problem. With everything that has been
said, no one has addressed the friction that occurs from the passing of
the knife over the paraffin block cut edge. Faster cutting would
increase this friction and a surfactant; i.e. water or soap, etc., would
help to decrease this friction. Also, I would think that the angle of
the knife to the block would affect this friction.
I know this doesn't solve the problem, but sometimes understanding what
is happening helps. I found it interesting that the polymers in the
paraffin need time not cold to harden.
Many years ago, I read an article in the Journal of Histotechnology
about a solution called Baker's softening solution. I made this
solution up using less phenol and find that it helps with what I have
always thought to be a friction problem. Many techs don't want to take
the time to soak their faced blocks, but I face all of my blocks and
when I can, I soak in Baker's softening solution. If I had no time
constrictions I would do this all of the time as the sections are
beautiful. For blocks with calcium I use the softening solution 1:1
with a decal solution. I do cut with a slow even motion.
This solution solved my problems with microchatter and when I cut deeper
into the block without soaking the microchatter returns.
For those of you that would like to try this solution, here are the
directions.
Modified Baker's Softening Solution (modified because the original
directions called for more phenol).
720 CC of 60% ROH
80 CC Glycerol
20 CC Acetone
20 CC Phenol
Mix well.
This stuff smells great and feels good on your hands too.
I surface the blocks, place them face up on the ice or cold plate and
cover the surface with a paper towel soaked in Bakers solution.
If you try this, I would appreciate hearing your thoughts on your
experience with it.
Priscilla Delventhal - Currently in New Hampshire on a traveling
assignment.